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Biomedical subjects

F Varga

Publications and source records attributed to F Varga.

At least 109 records · Page 6Linked to original sources
PubMed1975

Subepithelial capillary blood flow estimated from blood-to-lumen flux of barbital in ileum of rats.

The outflux of barbital from the blood into the small intestine perfused with an isosmotic buffer of pH 9.5 in anesthetized rats was measured to determine the subepithelial capillary blood flow in the gut. It was shown that barbital clearance is blood flow limited when total blood flow to the small intestine varied between 0.3 and 1.3 ml/min per g wet gut. The barbital clearance amounted to an average of 50.3% of the total blood flow. The total mucosal blood flow determined by the use of the distribution of microspheres in the layers of gut wall was 62.76% of the total blood flow. It is concluded that, because of anatomical reasons, a subepithelial blood flow available for the transport process is somewhat less than the measured total mucosal blood flow.

Animals↗
PubMed1975

Effect of gastric emptying rate on the intestinal absorption of chloroquine in rats.

After oral administration, chloroquine caused a dose-related delay in gastric emptying and in its own absorption from the small intestine in rats. Acetyl-beta-methylcholine (0.75 mg/kg i.p.) did not influence the intraperitoneal LD50 value of chloroquine (102 mg/kg) significantly, but reduced oral LD50 from 1,080 to 280 mg/kg. Acetyl-beta-methylcholine increased both the gastric emptying rate and the propulsion motility of the small intestine. As a consequence, the intestinal mucosal surface that had come into contact with the drug was increased in size, resulting in more rapid absorption of chloroquine. Infusion of chloroquine at a rate of 1 mg/min/kg into a mesenteric vein was tolerated by anaesthetized rats for hours. Increasing the dose, however, led to shorter survival times and eventually to death. It is concluded that gastric emptying may play an important role in the rate of intestinal absorption and in the oral toxicity of drugs.

Animals↗
PubMed1975

[Uptake of serum free fatty acids by lipids of the brown adipose tissue].

The flow rate of serum free fatty acids (FFA) into the lipids of brown adipose tissue (BAT) of newborn rabbits was determined by intravenous injection of [14C]-1-palmitate. For a normal 7 day old animal during acute cold exposure the flow rate is (1 hour in 20 degrees C ambient temperature) 0.209 mumol/minute, that is 3.6% of the serum FFA turnover. Prolonged cold exposure only induced an increase in FFA influx if the lipid depot had been depleted (48 hours starvation in 20 degrees C). Consequently, the BAT takes up serum FFA for heat production only after mobilisation of its lipid stores. It is supposed that the mechanism of the uptake of serum FFA by the BAT is connected with their esterification to triglycerides. The phospholipids of BAT which are not only membrane bound lipids are characterized by a high metabolism.

Adipose Tissue, Brown↗
PubMed1975

[The effect of cold and hunger on the free fatty acid metabolism in the serum of newborn rabbits].

A tracer kinetic study with [14C]-1-palmitic acid was carried out to study the influence of acute exposure to cold and starvation on free fatty acid (FFA) metabolism in serum of newborn rabbits. The turnover rate of serum FFA was 10.20 mumol/min in well fed rabbits kept in a thermoneutral environment (normal conditions). Cold exposure as well as starvation either in a cold or thermoneutral environment resulted in a diminution of the turnover rate, being the consequence of a significantly reduced pool of FFA. It was 9.57 mumol under normal conditions. The disappearance rate (1.07 min-1), half time (0.65 min) and turnover time (0.94 min) of well nourished animals was slightly, but mostly not significantly, influenced by cold exposure and starvation. The cold induced increase in serum FFA concentration and the decrease following restoration of thermoneutrality did not run parallel with changes in the absolute turnover rate.

Animals↗